Electronic devices (e.g., computers) have many different components that communicate with each other. As technologies are developed, components and corresponding communication protocols evolve. Often, there is a need to support backwards compatibility between a previous generation of components/protocols and a next generation of components/protocols. This is because upgrading to the next generation components/protocols (or corresponding devices) is expensive and may be unnecessary for many consumers. Thus, the upgrade process occurs over time and does not necessarily involve all consumer products or components.
One example of a developing technology is the Peripheral Component Interconnect (PCI) Express architecture. PCI Express implements serial communication lanes to support high-speed communications between different computer components and/or peripherals, where the number of serial communication lanes allocated to each component/peripheral can vary (e.g., 1×, 2×, 4×, 8×, 16× and so on). The PCI Express lanes fan out from an interconnect (i.e., a switch) that enables PCI Express components to communicate with each other and also that enables PCI Express components to communicate with the host system. Different interconnects provide similar functionality as dictated by the PCI Express specification, but may vary with respect to capability (e.g., the total number of components/peripherals that can be supported, the total number of communication lanes that can be supported, the configuration of lanes, etc.).
As do many technologies, PCI Express is evolving from one generation to a next generation (Gen1 to Gen2) and there is ongoing development for future generations (Gen3) yet to be implemented. The PCI Express specification mandates that Gen2 components be compatible with Gen1 components. In part, this means that Gen2 components and links (each link has one or more lanes) need to be able to operate at a Gen2 data rate (5.0 Gbps) and at a Gen1 data rate (2.5 Gbps). Providing efficient solutions to the backwards compatibility requirements of PCI Express or other communication architectures is desirable.